my BF and I were having dry sex on 14 Dec, 2-3 days after my previous period has ended. he had nothing on but had a towel wrapped around his waist, and I had my shorts and underwear on, but my shorts were rather short, barely covering my butt. we dry humped 2-3 times on that day, he did not ejaculate on me but I'm not sure if he had pre cum. today 24 Dec I experienced some brown spotting and cramps, could I be pregnant? as it seems too early now for my next period to come